3, 4-epoxycyclohexane carboxylic acid esters of di and tri ethylene glycol



' This invention relates to a new class .of organic com- 15 2,853,499 r v Patented Sept} 23, 1958 1' I 2- 2 853 499 and plasticizers forvarioussynthetic organic resins; and in addition yield permanent, non-migrating compositions 3,4-EPOXYCYCLOHEXANE CARBOXYLIC ACID which are very valuable in certain. commercial applica- ESTERS F DI AND TRI ETHYLENE GLYCOL 'tions such as, for example, surface coatings, laminates d plastic molding compositions. 3 1: Ben amin PhllllPS and Paul S. Starcher Charleston an a v.

W. Va., assignors to Union Carbide C orporation, 5 CPI-Pounds thlslllvennon are P q byihe epoxidatlon of the olefimc linkages contained in the startcorporatlon of New York V g Y mg material and may be'prepared by either of two oxidaollglllal aplfilcafloll October tion procedures, both -of. which are satisfactoryand ro rlal No. 385,026, new Patent No. 2,745,847, dated 10 Vida-Commercially acceptable yields; I

" 1956 Divided and this application November The. first oxidation method is called the acetaldehyde 1955 Senal 549842 monoperacetate method and the reaction whereby the 4 Claims. (Cl. 260-348) epoxides are formed may be illustrat'ed'by the following general equation:

pounds which are useful in plastics and resins industry. i: ZACETALDEHYDE MONOBERACETATE More particularly, this invention relates to a new class of ,METHOD 1 R: R1 a R: R2 I R; R1 6 f? R,

C0 R-O-C v Ra R0 CHr-C Re Ru 'Rt R5 R5" Br yRs R5 R5 I diepoxide compounds prepared from the cyloalphatic wherein R R R R repr sent hydrogen esters of polyhydric compounds. 5 atom or an aliphatic radical and R'repre'sents'a divalent The compounds of this invention may be conveniently organic radical. I i represented by the following general formula: The second oxidation method is called; the per-acetic R2 R: acid method and the reaction whereby the: epoxides are R3 R1 I R1 R3 formed may be illustrated by the followinggeneral equa- C 0 R 0 C 40 11011: Q f 0 r 1PERACETIC ACID METHOD f a R:Rg' 'RZRL R4 Re 6 R4 1 F 35/ Ba R1 wherein R R R R R and R represent a hydrogen atom or an aliphatic hydrocarbon radical and Rreprevsents a divalent organic radical such as, for example, an R aliphatic radical and an oxy-alkylene radical. More par- R5 R5 ticularly, the compounds of this invention are directed to R2 the dihydric alcohol diesters of acids selected from the Rs R1 (6 the general formula:

group consisting of 3,4-epoxycyclohexanecarboxylic acid and lower alkyl substituted 3,4-epoxycyclohexanecarbox- 0 ylic acids in which the hydroxyl groupsof said dihydric alcohols are este'rified bygsaid acids and wherein said di- R hydric alcohol is'a polyalkylene' glycol corresponding to R5 wherein R, R R R R R5 and' R are as above defined.

The use of peracetic acid as the oxidation agent is parno' om't ino ,.n i

X ticularly Well suited for the epoxidation reactionsince the wherein X represents members selected from the group cyclohexenyl ring is relatively easily converted tothe corconsisting of hydrogen and methyl groups and n repreresponding epoxy form. This particular ability of the sents a positive integer in the range of'from 2 through 3. peracetic acid and other peracids, in general, to promote The compounds of vthis invention are useful as modiclean-cut reactions and provide acceptable yields is not resins, and are. particularly adapted for use as stabilizers fiers =for commercially important synthetic condensation unusual in the art of oxidizing organic compounds for it 5 has long been recognized that the percarboXylic-acids 0ccupy somewhat f a unique position in the oxidizing reagent field since they are able to effect several specific types of chemical transformations with acceptable eificiencies, while other powerful oxidizing reagents, such as potassium permanganate are not.

One such type of chemical transformation that the peracids are able to effect is that type of reaction which makes available the compounds of this invention, that is, the oxidation of unsaturated organic compounds to produce the corresponding epoxidcs.

The unsaturated cycloaliphatic carboxylic acids which are used in the preparation of the starting materials of this invention may be prepared by reacting butadiene or the homologues of butadiene with alpha, beta-unsaturated aliphatic aldehydes, such as, for example, acrolein, methacrolein, crotonaldehyde and the like to yield the corresponding unsaturated cycloaliphatic aldehyde which in turn may be subjected to known oxidation procedures to yield the corresponding unsaturated cycloaliphatic carboxylic acids. Typical unsaturated aldehydes suitable for use in preparing the cycloaliphatic acids are reported in the literature by Sobecki, Ber. 43, 1040 (1910); Diels and Alder, Ann. 460, 106, 121 (1928); Ann. 470, 62-103 (1929) and in their U. S. Patent 1,944,731.

These unsaturated cycloaliphatic carboxylic acids may be readily reacted with aliphatic dihydric compounds to yield the corresponding unsaturated cycloaliphatic diester of the aliphatic dihydric compound.

The following list sets forth series of dihydric alcohols which are suitable for use in preparing the compounds of this invention:

(A) 1,2-glycols:

Unsaturated glycols (A) Olefinic glycols: 1-butene-3,4-dio1 2-butene-1,4-diol (B) Diolefinic glycols:

1,5-hexadiene-3,4-diol 2,6-octadiene-4,5-diol (C) Acetylenic glycols:

2-butyne-1,4-diol 3-hexyne-2,5-diol 2,5-dimethyl-3-hexyne-2,5-diol Glycol derivatives (A) Polyethylene glycols: Diethylene glycol Triethylene glycol Dipropylene glycol As may be readily understood, the products of this invention are particularly attractive in view of the fact that they are potentially low cost chemicals since butadiene, homologs of butadiene and the alpha, beta-unsaturated aldehydes are economical starting materials and the steps required to produce the epoxides are conducted with high efliciencies.

The following examples will serve to illustrate the practice of the invention:

EXAMPLE 1.-PREPARATION OF DIETHYLENE GLYCQL BIS- 3,PEPOXYCYCLOHEXANECARBOXYLATE) Two hundred and fifty grams of diethylene glycol bis-(3-cyclohcxenecarboxylate) were heated in a flask with agitation to 40 C. Then 833 grams of 21.3 percent solution of peracetic acid in acetone (177 grams, 2.33 mols of peracetic acid) were added dropwise over a period of two hours. The reaction solution was maintained at 40 C. by cooling with a cold water bath. After addition was complete, the reaction conditions were maintained for an additional four hours, whereupon an analysis indicated that all of the peracetic acid had been consumed.

After being stored at 11 C. for sixteen hours, the reaction solution was mixed with 2200 grams of ethylbenzene and the resulting solution distilled under reduced pressure at a maximum temperature of 50 C. After the 'loW-boiling material had been stripped ofi, there was obtained 278 grams of residue product which analyzed 89.5 percent as diethylene glycol bis-(3,4-cpoxycyclohexanecarboxylate) by determination for epoxide groups, 3.8 percent as unreacted diethylene glycol bis-(B-cyclohexenecarboxylate) by determination of double bonds, and 0.38 percent acidic impurities calculated as acetic acid. The yield of the diepoxide product was 89.5 percent of theory.

EXAMPLE 2.PREPARATION 0F 2-ETHYL-1,3-HEXANE- DIOL BIS-(3,4-EPOXYCYCLOHEXANECARB OXYLATE) To one hundred and fifty-seven grams of 2-ethyl-l,3- hexanediol bis-(3-cyclohexenecarboxylate) (0.434 mol) there was added dropwise, over a period of one and onehalf hours, three hundred and thirty eight grams of a 24.5 percent solution of peracetic acid in acetone (83 grams, 1.095 mols of peracetic acid). The reaction solution was stirred and kept at 22-25 C. by immersing the reaction fiask in a cool water bath. After the addition was complete, the reaction conditions were maintained the same for four and one-half hours longer and then the solution was stored at 11 C. for sixteen hours. Analysis at the end of this time indicated 94 percent of the theoretical amount of peracetic acid had been consumed.

The reaction solution was then added dropwise to a still kettle containing 500 grams of ethylbenzene refluxing at 55 C. at 35 mm. of Hg pressure and during addition, acetic acid, peracetic acid, acetone, and ethylbenzene were distilled oii at the top of the kettle. After addition was complete, all low-boiling constituents were stripped oif up to a temperature of C. at 3 mm. of Hg pressure. There was obtained, as residue product, 166 grams of a hazy viscous liquid which analyzed 86.8 percent as 2 ethyl-1,3-hexanediol bis-(3,4-epoxycyclohexanecarboxylate) by analysis for epoxide groups and 10.2 percent as unreacted 2-ethyl-l,3-hexanediol bis-(3-cyclohexenecarboxylate) by analysis for double bonds. The yield of the diepoxide product was 84.3 percent of theory.

EXAMPLE 3.PREPARATION 0F DIETHYLENE GLYCOL BIS-(G-METHYL 3,4 EPOXYCYCLOHEXANECARBOX- YLATE) Two hundred and ninety-seven grams of diethylene glycol bis-(6 methyl 3 cyclohexenecarboxylate) were added dropwise, over a two hour period, with stirring at a temperature of 25.30 C., to 670 grams of a 21.2 percent solution of peracetic acid in acetone (161 grams, 2.122 mols of peracetic acid). The reaction solution was maintained at the above-mentioned temperature by immersing the flask in a water bath and after addition was complete, the reaction conditions were maintained for an additional four hours whereupon the solution was stored for sixteen hours at -11 C.

The reaction solution was then fed dropwise into a still kettle containing 1000 grams of ethylbenzene refluxing at 45 'C. at 35 mm. of Hg pressure and acetone, acetic acid, peracetic acid, and ethylbenzene were distilled olf. After addition was complete, the product was stripped of low-boiling constituents up to a kettle temperature of 90 C. at 2 mm. of Hg pressure. There was obtained as residue product, 330 grams of amber-colored viscous liquid which analyzed 86.4 percent purity as diethylene glycol bis-(6-methyl-3,4-epoxycyclohexanecarboxylate) by analysis for epoxide groups and 13.0 percent as unreacted diethylene glycol bis-(6-methyl-3-cyclohexenecarboxylate) by analysis for double bonds. The yield was 87.8 percent of theory.

EXAMPLE 4.PREPARATION 0F 3-METHYL-1,5-PEN- TANEDIOL BIS (3,4 EPOXYCYCLOHEXANECAR- BOXYLATE) Six hundred sixty-three grams of a 24.0 percent solution of peracetic acid in acetone (159 grams, 2.097 mols, of peracetic acid) were fed dropwise over a period of two hours ten minutes to 220 grams (0.839 mol) of 3-methyl- 1,5-pentanediol bis-(3-cyclohexenecarboxylate) stirring at 20-50" C. After addition was complete, the solution was allowed to react under the same conditions for two and one-half hours longer, at which time analysis indicated that all of the peracetic acid had been consumed.

The reaction solution was stored at --11 C. for sixteen hours and then was fed dropwise into a still kettle containing 1000 grams of ethylbenzene refluxing at 45 C. at 35 mm. of Hg pressure. During the addition, acetone, acetic acid, peracetic acid, and ethylbenzene were distilled oflf at the top of the kettle. The product was stripped of low-boiling constituents to a kettle temperature of 90 C. at 2 mm. of Hg pressure and there were obtained 314 grams of light yellow viscous liquid residue product which analyzed 96.3 percent as pure 3-methyl-1,5-pentanediol bis-(3,4-epoxycyclohexanecarboxylate) by epoxide analysis, and 7.65 percent unreacted 3-methyl-l,5-pentanediol bis-(3-cyclohexenecarboxylate) by analysis for double bonds. The yield was 88.3 percent of theory.

EXAMPLE 5.PREPARATION OF 2-METHOXYMETHYL- 2,4DIMETHYL 1,5 PENTANEDIOL BIS-(3,4-EPOXY- CYCLOHEXANECARBOXYLATE) Seven hundred forty-five grams of a 21.0 percent solution of peracetic acid in acetone (156 grams, 2.019 mols of peracetic acid) were fed dropwise over a period of three hours fifteen minutes to 264 grams (0.673 mol) of 2- methoxy-methyl-2,4-dimethyl-1,S-pentanediol bis (3 cyclohexenecarboxylate) stirring at 40-50 C. After addition was complete, the reaction was allowed to proceed under the same conditions for three more hours and then stored for sixteen hours at 11 C.

The reaction solution was then fed dropwise into a still kettle containing 1800 grams of ethylbenzene refluxing at 45 C. at 35 mm. of Hg pressure. During the addition, acetone, acetic acid, peracetic acid and ethylbenzene were distilled otf at the top of the kettle. The product was stripped of low-boiling constituents to a kettle temperature of 85C. at 3 mm. of Hg pressure. There were obtained 274 grams of residue which was 72.5 percent 2-methoxymethyl-2,4-dimethyl-1,S-pentanediol bis (3,4- epoxycyclohexanecarboxylate) by epoxide analysis and 6.0 percent unreacted 2-methoxy-2,4-dimethyl-1,5-pentanediol bis-(3-cyclohexenecarboxylate) by analysis for double bonds. The yield was 69.6 percent of theory. EXAMPLE 6.PREPA'RATION OF TRIETHYLENE GLY- COL BIS-(3,4-EPOXYCYCLOHEXANECARBOXYLATE) Nine hundred fifty-five grams of a 21.0 percent solution of peracetic acid in acetone (200 grams, 2.64 mols, of peracetic acid) were fed dropwise over a period of three hours fifteen minutes to 322 grams (0.88 mol) of triethylene glycol bis-(3-cyclohexenecarboxylate) with stir- The reaction was very exothermic and the temperature of the reaction solution 6 was maintained at -50 C. by immersing the flask in a cold water bath. After addition was complete, the reaction conditions were maintained for an additional two and one-half hours, at which time analysis indicated that all of the peracetic acid had been consumed.

The reaction solution was stored for sixteen hours at -11 C. and then added dropwise to a still kettle containing 2500 grams of ethylbenzene refluxing at 40 mm. of Hg pressure. Acetone, acetic acid, peracetic acid and ethylbenzene were distilled oif at the top of the kettle during the addition and the kettle residue was finally stripped oflow-boiling constituents up to 70 C. at 3 mm. of Hg pressure. There were obtained 355 grams of viscous liquid analyzing 79.6 percent as triethylene glycol bis-(3,4-epoxcyclohexanecarboxylate) by epoxide group analysis and 8.1 percent unreacted triethylene glycol bis- (S-cyclohexenecarboxylate) by analysis for double bonds.-

The yield of diepoxide was 80.8 percent of theory. V

EXAMPLE 7.PREPARATION 0F 1,5-PENTANEDIOL BIS- (3,4-EPOXYCYCLOHEXANECARBOXYLATE) Nine hundred forty-five grams of a 21.0 percent solution of peracetic acid in acetone (198 grams, 2.61 mols, of peracetic acid) were fed dropwise over a period of two hours ten minutes to 278 grams (0.87 mol) of 1,5-pentanediol bis-(3-cyclohexenecarboxylate) with stirring at 40-50 C. The reaction conditions were maintained for an additional two hours and forty-five minutes after addition was complete and then the solution was stored for sixteen hours at 11 C.

The reaction solution was added dropwise to a still kettle containing 2500 grams of ethylbenzene refluxing at 40 mm. of Hg pressure and acetone, acetic acid, peracetic acid, and ethylbenzene were distilled off at the top of the kettle. After addition was complete, all low-boiling constituents were stripped off up to a kettle temperature of 70 C. at 3 mm. of Hg pressure. There were obtained 311 grams of residue product which analyzed 84.3 percent, 1,5-pentanediol bis-(3,4-epoxycyclohexanecarboxylate) by analysis for epoxide groups and 6.94 percent unreacted l,5-pentanediol bis-(3-cyclohexenecarboxylate) by analysis for double bonds. The yield was 84.6 percent of theory.

EXAMPLE 8.PREPARATION or ETHYLENE GLYCOL BIS-(3,4-EPOXYCYCLOHEXANECARBOXYLATE Sixteen hundred eighty grams of a 24.9 percent solution of peracetic acid in acetone (418 grams, 5.5 mols, of peracetic acid) were fed dropwise over a period of four hours to 613 grams (2.2 mols) of ethylene glycol bis-(3-cyclohexenecarboxylate) with stirring at 3540 C. On completion of the addition, the reaction was allowed to proceed under the same conditions for an additional four hours and then the reaction solution was stored for sixteen hours at 1l C. At this time, analysis showed that 98.8 percent of the peracetic acid had been consumed.

The reaction solution was dissolved in 1600 grams of ethylbenzene and then distilled to remove all low-boiling constituents up to a kettle temperature of 70 C. and 2 mm. of Hg pressure. There were obtained 614 grams of residue product which analyzed 83.8 percent as ethylene glycol bis-(3,4-epoxycyclohexanecarboxylate) by analysis for epoxide groups, 5.0 percent unreacted ethylene glycol bis-(3-cyclohexenecarboxylate) by analysis for double bonds, and 0.5. percent acidic impurities calculated as acetic acid. The yield was 75.4 per cent of theory.

EXAMPLE 9.PREPARATION 0F 1,6-HEXANEDIOL BIS- (3,4-EPOXYCYCLOHEXANECARBOXYLATE Five hundred and eighty-four grams of 1,6-hexanediol bis-(3-cyclohexenecarboxylate) (1.75 mols) were placed in a flask and 1560 grams of a 25.5 percent solution of peracetic acid in acetone was added over a four hour period. The reaction was exothermic and the solution was maintained at 35-40 C. by cooling with an ice the reaction conditions were maintained for an additional one hour.

The reaction solution was fed dropwise into a still kettle containing 1750 grams of ethylbenzene'refiuxing at 25 mm. of Hg pressure. Acetone, acetic acid, peracetic acid, and ethylbenzene were distilled off at the head during the addition period. After all of the reaction solution had been added, the residue product was stripped of ethylbenzene and there were obtained 665 grams of product analyzing 88.6 percent as 1,6-hexanediol bis-(3,4- epoxycyclohexanecarboxylate) by analysis for epoxide groups and 3.5 percent as unreacted diene by analysis for double bonds. The yield of diepoxide corresponded to 92 percent of theory.

This application is a division of copending application, Serial No. 385,026, filed October 8, 1953, now U. S. 2,745,847.

What is claimed is:

1. The dihydric alcohol diesters of acids selected from 8 the group consisting of 3,4-epoxycyclohexanecarboxylic acid and lower alkyl substituted 3,4-epoxycyclohexanecarboxylic acids in which the hydroxyl groups of said dihydric alcohols are esterified by said acids and wherein said dihydric alcohol is a polyalkylene glycol correspondingto the general formula:

wherein X represents members selected from the group consisting of hydrogen, and methyl groups and I represents a positive integer in the range of from 2 through 3.

2. Diethylene glycol bis-(3,4 epoxycyclohexanecarboxylate).

3. Diethylene glycol bis-(6-methyl-3,4-epoxycyclohexanecarboxylate).

4. Triethylene glycol bis-(3,4 epoxycyclohexanecarboxylate).

No references cited. 

1. THE DIHYDRIC ALCOHOLDIESTERS OF ACIDS SELECTED FROM THE GROUP CONSISTING OF 3,4-EPOXYCYCLOHEXANECARBOXYLIC ACID AND LOWER ALKYL SUBSTITUTED 3,4-EPOXYCYCLOHEXANECARBOXYLIC ACIDS IN WHICH THE HYDROXYL GROUPS OF SAID DIHYDRIC ALCOHOLS ARE ESTERFIED BY SAID ACIDS AND WHEREIN SAID DIHYDRIC ALCOHOL IS A POLYALKYLENE GLYCOL CORRESPONDING TO THE GENERAL FORMULA: 